FIELD-aligned irregularities in the F-region of the ionosphere cause amplitude and phase scintillations of satellite radio transmission 1-5. It seems that scintillations increase in magnitude and number towards the northern and southern auroral zones. The latitudinal variation is, however, masked by the enhancement of scintillations whenever the angle between the ray path and the magnetic field-the aspect angle-is small. Thus, at recording stations from subauroral4,6 to low2 latitudes, strong scintillations are observed towards the equator.